Louis Pasteur, a French chemist, born in Dole, Dec. 27, 1822. He took his degree in 1847, was professor of physical sciences at Dijon from 1848 to 1849, and afterward of chemistry at Strasburg till 1854, when he organized the new faculty of science at Lille. In 1857 he went to Paris as scientific director of the normal school; subsequently he was elected a member of the institute; and toward the end of 1863 he assumed the chair of geology, physical science, and chemistry at the school of fine arts, and afterward that of chemistry at the Sorbonne. He acquired great celebrity, and received in 1856 the Rumford medal for his researches on the relation of the polarization of light with hemihedrals in crystal and other researches, a French prize for his works on fermentation in 1859, and a Jecker prize in 1861 for his chemical labors. In 1873 he was elected an associate member of the academy of medicine, and the government granted him in 1874 a pension of 20,000 francs. He is most widely known for his opposition to the doctrine of spontaneous generation, and his researches in fermentation. He maintains that all fermentations are processes connected with life, and not of spontaneous production, but that the living organism must proceed from a parent of the same kind.
Therefore fermentation can never take place if all access of germs to a fermentable substance is prevented. He has invented a new process for the fermentation of beer founded upon his theories, a part of which consists in excluding atmospheric air from the fermenting wort, as he maintains that fermentation can be conducted without the presence of free oxygen, and under certain circumstances proceeds more satisfactorily in an atmosphere of carbonic acid. He discovered that glycerine is one of the products of fermentation. (See Fermentation.) He also made interesting researches on racemic acid, discovering that when racemate of ammonium is mixed with a small quantity of beer yeast and exposed to a temperature of 85° F. fermentation takes place, and the racemic acid is converted into lsevotartaric acid. His principal works, besides his contributions to the Annales de chimie et dephysique, are: Nouvel exemple de fermentation determine par des animalcules infusoires pouvant vivre sans oxygene libre (Paris, 1863); Etudes sur le vin, ses maladies, etc. (1866); Etudes sur le mnaigre, etc. (1868); Etudes sur la maladie des vers d soie (2 vols., 1870); and Quelques reflexions sur la science en France (1871).